Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/0065—Specific aspects of external EGR control
  • F02D41/0072—Estimating, calculating or determining the EGR rate, amount or flow
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/45—Sensors specially adapted for EGR systems
  • F02M26/46—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition
  • F02M26/47—Sensors specially adapted for EGR systems for determining the characteristics of gases, e.g. composition the characteristics being temperatures, pressures or flow rates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/52—Systems for actuating EGR valves
  • F02M26/53—Systems for actuating EGR valves using electric actuators, e.g. solenoids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0002—Controlling intake air
  • F02D2041/0017—Controlling intake air by simultaneous control of throttle and exhaust gas recirculation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/04—Engine intake system parameters
  • F02D2200/0402—Engine intake system parameters the parameter being determined by using a model of the engine intake or its components
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/04—Engine intake system parameters
  • F02D2200/0411—Volumetric efficiency
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/04—Engine intake system parameters
  • F02D2200/0414—Air temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D41/0047—Controlling exhaust gas recirculation [EGR]
  • F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
  • F02D41/0052—Feedback control of engine parameters, e.g. for control of air/fuel ratio or intake air amount
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/40—Engine management systems

Definitions

• the present invention relates to a method of c air loop of a diesel engine using a model (volumetric.
• the field of the invention is, in a general manner, diesel and more particularly that of the control of a rate of exhaust gas recirculation rate commonly (Exhaust Gas Recirculation in English) for a motei reinjection
• a rate of exhaust gas recirculation rate commonly Exhaust Gas Recirculation in English
• a part of the exhaust gas at the level of the engine is intended to limit the emissions of oxides of azo formation of nitrogen oxide is mainly due to the high temperatures of the combustion chambers under heavy loads.
• Qair is the flow of fresh air sucked and Qegr is the flow of recycled exhaust.
• the response time on the intake pressure results, via an error on the total flow rate O, by an error on the EGR T rate.
• JP9088649 a method of controlling the air loop by regulating the recycled exhaust gas rate estimated from an instrumentation in pressure, temperature, and by means of a fresh air flowmeter.
• JP4314953 a method of controlling the air loop by regulating the rate of recycled exhaust gas. This rate of recycled exhaust gas is correlated with the combustion temperature determined from the cylinder pressure. The engine must therefore be equipped with pressure sensors in the cylinders.
• JP63134845 a method of controlling the air loop by regulating the recycled exhaust gas rate estimated from a cylinder pressure instrumentation and defined from a flow meter of fresh air.
• the control of the air loop is based on the fact that the overall gas flow sucked by the engine is estimated using the knowledge of the engine volumetric efficiency.
• the air loop control is also based on the fact that effects related to the volume of the intake manifold are taken into account. Among these effects, phenomena of mass accumulation are observed in the intake manifold.
• the flow of recycled exhaust gas is calculated from a Barre de St-Venant relationship applied to the recycled exhaust gas circuit.
• a second problem solved related to this type of control is to make available to the engine control computer an indicator of the gas rate recycled exhaust system reliable and accurate both in the stabilized phases and transient engine operating, because of the estimation of the overall flow sucked by the engine.
• This solution is preferably obtained by providing a fresh air flow rate indicator as close as possible to the engine inlet, which optimizes, among other things, the management of operating transients and limits smoke emissions.
• Last but not least, the removal of the air flow meter and / or cylinder pressure sensors that are technologically difficult to implement, is also possible by controlling the air loop according to the recycled exhaust rate indicator and / or the air flow indicator.
• This invention therefore relates to a control method that can be used directly on an engine during operation.
• This method can be integrated in the calculator of a direct injection diesel engine using at least one intake air mixture gas and recycled exhaust gas temperature sensor, an engine intake pressure sensor and an exhaust pressure sensor. .
• the subject of the invention is therefore a method for controlling an air loop of a diesel engine with direct injection using a computer, in which air is mixed with a recycled portion of the gases. engine exhaust,
• a first overall flow rate of the mixture is determined, - a mass accumulation of the mixture in the collector is estimated by means of a manifold model, to determine a second overall flow at the manifold inlet,
• a new flow rate of the recycled exhaust gases is calculated by a formulation of the Barrier de St Venant type applied to a section restriction of a valve of the recycled exhaust gas, this new flow rate of the recycled exhaust gases is combined with the second overall flow rate to calculate an effective exhaust gas recirculation rate and an effective fresh air flow,
• FIG. 1 a schematic representation of a global implementation architecture of the method according to the invention
• FIG. 2 a schematic representation of a one-dimensional isentropic flow for a compressible fluid of the EGR type
• the method according to the invention applies to the air loop of a diesel engine with direct injection known as common rail or injectors-pumps.
• FIG. 1 represents an overall architecture for the implementation, in an engine control computer, of the method for controlling the recycled exhaust gas rate and the air flow, according to the invention. This involves determining in the engine control computer reliable information on the total flow of air / EGR gas sucked by the engine and on the flow of EGR gas. Combined with a mass accumulation model in the intake manifold, these two pieces of information make it possible to estimate the total recycled exhaust rate and the fresh air flow rate at the intake manifold inlet.
• the method relies on two estimates based on engine parameters, which can be either measured, mapped or modeled.
• FIG. 1 shows an air metering device 1 which makes it possible to mix, in an intake manifold 2, air accepted by an air inlet 3 and a recycled part of the exhaust gases supplied via a duct 4.
• the mixture is sucked by a motor 5 using the intake manifold 2.
• a sensor 6, placed in the manifold 2 measures a temperature intake T2 of the mixture and an inlet pressure P2 of the mixture.
• the sensor 6 according to the invention is placed between the metering device 1 and the outlet of the collector 2 in the engine 5. More exactly, the sensor 6 is placed downstream of a mouth 7 where the recycled exhaust gases enter the collector 2.
• the sensor 6 can be broken down into two sensors: one for the temperature, the other for the pressure.
• a solenoid valve 10 is placed in the pipe 4 connected to the exhaust manifold 9. It allows to take gas from the exhaust to the engine intake. It is controlled by a calculator 1 1, and allows to measure the rate of recycling of exhaust gas.
• a memory 12 of programs is connected to the computer 1 1 by a bus. The memory 12 includes a program. This program allows:
• a regulation following a pre-check 18 a rate Tegr of exhaust gas recirculation and air flow Qair according to this estimate and predefined setpoints 19 and 20; the instruction 19 is relative to the recycled exhaust gas rate and the instruction 20 corresponding to the air flow.
• the determination steps 13, 13 estimation and 15 calculation are described more precisely in the following paragraphs.
• the overall flow rate Q14 of the motor 5 is given by:
• T2 Engine inlet temperature measured (in ° K)
• P2 Engine inlet pressure measured (in Pa)
• N Engine speed (rpm)
• Cylinder capacity Engine displacement (in m 3 )
• ⁇ M is the mass accumulation in the distributor following the variations of P2 and T2
• ⁇ t is the time interval during which the mass measurements M have been carried out.
• the calculation is described by means of FIG. 2 which represents a one-dimensional isentropic flow for a compressible fluid of the EGR type.
• the estimate of the Qegr flow rate of recycled exhaust gases is based on a St-Venant type of Barré formulation applied to the circuit. recycling. This model therefore requires knowledge or estimation of the following parameters.
• P8 is the pressure upstream of the solenoid valve 10 which corresponds to the pressure in the exhaust manifold 9. This pressure P8 can be measured, but a model based on either maps or a cylinder pressure signal will be preferred.
• T8 is the temperature of the gases upstream of the solenoid valve 10 which corresponds to the temperature of the gases in the exhaust manifold 9. This temperature T8 can be measured, but a model based on cartography or other is preferred.
• P2 is the pressure downstream of the solenoid valve 10. This pressure will be considered equal to the pressure in the intake manifold 2, often referred to as supercharging pressure.
• T2 is the temperature of the gases downstream of the solenoid valve 10 which corresponds to the temperature of the gases in the intake manifold 2. This temperature T2 can be measured, but a model based on cartography or otherwise is preferred.
• ⁇ A is the product of the ⁇ discharge coefficient of the solenoid valve 10 by the geometric section A. This information comes from a table depending on the solenoid lift. The calculation is defined by the following formula:
• dm / dt represents the temporal variation of mass whose temporal integration leads to the mass to be considered.
• K is a constant.
• Figure 3 shows an evolution of three different recycled exhaust rates for an automobile acceleration ranging from 100 to 120 km / h: in 21 the result with the control of the air loop of the state of the technical, in the result with the control using the volumetric efficiency model ⁇ vol according to the invetion, and 23 the set to be respected. It clearly appears that the control of the air loop according to the invention is more faithful to the instruction than in the prior art.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Analytical Chemistry (AREA)
• Exhaust-Gas Circulating Devices (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2007
  • 2007-06-22 FR FR0755950A patent/FR2917784B1/fr not_active Expired - Fee Related
• 2008
  • 2008-06-09 WO PCT/FR2008/051019 patent/WO2009001015A2/fr not_active Ceased
  • 2008-06-09 EP EP08805955A patent/EP2158392A2/de not_active Withdrawn

Non-Patent Citations (1)

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